Various services referred to as group services are known in communication networks, such as third generation mobile radio networks. These are services which are used by participants or members in a group. Examples of group services which are known in mobile radio networks are Instant Messaging (IM), Push-to-Talk-over-Cellular (PoC), gaming applications or else the “Presence” service. In this case, the data from the group service can be transmitted from and/or to the participants in the group either on a packet-switched basis or else on a circuit-switched basis, depending on the respective group service.
Various services and applications are currently being standardized for the mobile radio sector within the framework of the “Open Mobile Alliance (OMA)”. In addition to individual group services, such as Push-to-Talk-over-Cellular, the OMA is also developing specifications which are relevant to the general architecture of group services. Thus, section 5.1.3 of the document “XML Document Management Requirements, Candidate Version 1.0-17 Mar. 2005, Open Mobile Alliance, OMA-RD-XDM-V1—0-20050317-C” discloses the option of defining groups which can be used for a plurality of group services. Thus, by way of example, one and the same group can be used for the group services Instant Messaging and Push-to-Talk-over-Cellular.